Sibling Camraderie

As Tiny Boy grows bigger I like to see my children change from a baby and a preschooler into a pair of kids and, more importantly, friends. They've just started playing together during the past few weeks and it makes my heart swell.
The down side of this new-found friendship between them is the game they choose to play. In this game, one claps one's hands over one's ears and repeatedly runs the length of the house all the while testing one's lung capacity with the loudest, shrillest screams one can muster.
How great would it be if they could cultivate the foundation of their brother-sister relationship by playing checkers? Better yet, the quiet game! I think I'll give them the suggestion and see how it's received.